docs: def update_context(app, pagename, templatename, context, doctree):
      """ Remove sphinx-tabs CSS and JS asset files if not used in a page """
      if doctree is None:
          return
      visitor = _FindTabsDirectiveVisitor(doctree)
      doctree.walk(visitor)
      if not visitor.found_tabs_directive:
          paths = [posixpath.join('_static', 'sphinx_tabs/' + f) for f in FILES]
          if 'css_files' in context:
              context['css_files'] = context['css_files'][:]
              for path in paths:
                  if path.endswith('.css'):
                      context['css_files'].remove(path)
          if 'script_files' in context:
              context['script_files'] = context['script_files'][:]
              for path in paths:
                  if path.endswith('.js'):
                      context['script_files'].remove(path)